1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to re-transmission of reconfiguration messages.
2. Background
Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division—Code Division Multiple Access (TD-CDMA), and Time Division—Synchronous Code Division Multiple Access (TD-SCDMA). The UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSPA), which provides higher data transfer speeds and capacity to associated UMTS networks.
As the demand for mobile broadband access continues to increase, research and development continue to advance wireless technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications. Recently, consumer and network operator demand for better and more reliable network performance has resulted in the need for improved over the air (OTA) reconfiguration signaling.
In 3GPP and other cellular systems, a network sends signaling messages to a user equipment (UE) to maintain radio resource control (RRC) connection and configure/re-configure radio resources. The UE sends a layer 2 acknowledgement (L2 ACK) to the network followed by a reconfiguration complete message upon completion of the reconfiguration at the UE, and waits for a L2 ACK from the network.
However, the UE may not receive a L2 ACK from the network or the network may fail to send the L2 ACK to the UE. The reason for this may include bad radio frequency (RF) conditions or enhanced dedicated channel (E-DCH) allocation not sufficient enough for the successful delivery of L2 ACK messages from the network. As a result, the UE may lose synchronization with the network and may drop the call.
Additionally, the UE may not be able to make a mobile originated (MO) call because of not receiving L2 ACK for initial direct transfer for a long time and the recovery from such scenarios may even take longer. In such scenarios, radio link layer (RLC) of the UE can trigger a RLC RESET to synchronize with the network.
Furthermore, the time the UE waits for a L2 ACK before initiating a RLC RESET or retransmission of reconfiguration complete message depends on UE RLC configuration parameters, for example, Timer_Poll and Max_Dat, configured by the network. If the current approaches are used, the UE may wait a long time to recover from scenarios described above and may result in call drops or UE call origination failures.
Therefore, there is a desire for improved re-transmission of reconfiguration messages.